Manufacture of water-soluble ester-like derivatives of vat dyestuffs



Patented May WILHELMI BAUER, OF WIESD FIRM:

MANUFACTURE No Drawing. Application filed October OBI, NEAR LEVERKUQEN, DURAND 8a HUGUENIN S. A., OI BASEL,

GERMANY, ASSIGNOB TO THE SWITZERLAND.

OF WATER-SOLUBLE ESTER-LIKE DERIVATIVES 01! VAT DYESTUI'FS.

The specification of the U. S. Letters Patout No. 1,448,251 discloses a process for the manufacture of water-soluble ester-like derivat-ives of vat-dyestuffs especially valuable for dyeing and ing in dyestuifs with a printing purposes, treating the leuco compounds of consistvat halogenide of a polybasic acid, especially with chlorosulphomc acid in presence of a tertiary base water with or without the ferent diluent.

by exclusion of use of an indif- Now I have found: that the same products can be obtained by replacing the chlorosulphonic acid by 5 acid (Cl-SO ride can be prod and it has also when it is used, water in the leuco of the chloride the chloride of pyrosulphuric --OSO --Cl). This chloat very low expense need the great advantage that a very small quantity of compound is harmless and has only the effect of a corresponding part being also transformed into the active chlorosulphonic acid. The yields of ester are nearly quantitative.

The following examples illustrate the improved process, the parts being by weight.

Ewwmple I To a mixture of 100 parts of dimethylaniline and 150 parts ed drop by drop,

of chlorobenzene are addin the cold, parts of chloride of pyrosulphuric acid and 30 parts of dry dibromindigo white and the whole is stirred for some soda.

c the chlorobenzene for half an hour. is then poured into a solution of To eliminate time in the cold. Then the temperature is allowed to rise within 6 hours,

to 60 C. The mass 65 parts of the dimethylaniline and it is subjected to distillaand while stirring continuously,

and maintained and salted out.

The yield of pure ester in the form of sodium salt amounts to 85% of the theory.

Dibromindigo i s obtained from indigo by 15, 1926, Serial No. 141,879,

and in Germany October 26, 192-5.

brominating the same and corresponds to the following formula:

E warmple I I Instead of 30 parts of dibromindigo white,

I use 25 parts of a dry leuco compound of 4.5-7-trichlorindigo, as obtained in a known Way, and thus obtain with a very good yield, the corresponding ester which, after development, dyes the fibre violet. The 4.5'7'-trichlorindigo corresponds to the following formula:

Cl 0 0 cl If in Example I the 30 parts of dibromindigo white are replaced by the corresponding quantity of a leuco compound of another vatdyestu for example of the thioindigo or anthraquinone class, the reaction proceeds similarly.

hat Iclaim is 1. A process for the manufacture of stable derivatives of vat-dystutfs in solid form, soluble in water and especially valuable for dyeing and printing purposes, consisting in treating a leuco com ound of a va't dyestuif with the chloride 0 pyrosulphuric acid in presence of an organic base. I

2. A rocess for the manufacture of stable derivatives of vat-dyestufis in solid form, soluble in water and especially valuable for dyeing and printing purposes, consisting in treating a Team compound of an indigoid vat-dyestuif with the chloride of pyrosulphuric acid in presence of an organic base.

In witness whereof I have hereunto signed my name this 1st da of October 1926.

\ W ILHELM BAUER.

above mentioned 

